Assessment Of Response For Rainfall During Summer Over East China To Sea Surface Temperature Anomalies Based On GEFA

Using the latest development calculation of the generalized equilibrium feedback assessment (GEFA, combined with the empirical orthogonal decomposition (EOF) and rotated EOF analysis method, we try to find the main influence SST abnormal modes to east China’s three kinds of abnormal summer precipitation patterns and regional rainfall, based on the NCEP-DOE2sea surface temperature(SST) reanalysis data and NCEP/NCAR wind and geopotential height data between1951to2010, accompany with140stations mean monthly precipitation data, which come from China climate center, and make some discussions to how precipitation response happen by circulation changing, main conclusions as we shown:(1) The rain pattern with Jianghuai has less precipitation but north of the Yellow River basin and southern China has more rain pattern(Ⅰ rain pattern) has most significant response to the positive phase of north Atlantic second mode. The precipitation pattern of Yellow River-the Yangtze River area with more rain but north of the Yangtze River and south of Yellow River with less rain(Ⅱ rain pattern) has remarkable positive response to positive phase of north Pacific U-similar mode and India ocean consistent cooling mode. The negative phase of third tropical Pacific SSTA mode and India ocean consistent warming mode has strong force to the rainfall pattern with more rain in the south of Yangtze River and less rain in the north(Ⅲ rain pattern)(2) The response character of each area’s precipitation anomaly to each sea basin SSTA mode have different characters. Northwest region’s precipitation anomalies are closely related to tropical SSTA, when tropical Pacific SSTA distribution is similar to El Nino mode, Northwest region will get more rainfall; The precipitation anomalies in Jianghuai region are influenced by mid-latitude and tropical SSTA at the same time, Jianghuai rainfall has remarkable response to tropical Pacific SSTA La Nina Modoki mode and the third mode、north Atlantic tripole mode and the second mode; Southwest regional precipitation anomalies are linked to mid-latitude SSTA, when north Atlantic SSTA distribution like the tripole and the second mode, the region’s rainfall will reduce.(3)The response of Circulation anomalies to SSTA mode has similar characteristics to precipitation’s circulation character. For example, El Nino Modoki mode excitation geopotential height positive anomaly over the east Asia continent in middle and high latitudes, the generated anticyclone circulation anomalies cause less rain in north of the Yangtze river, and the generated cyclone circulation in lower latitudes by geopotential height negative anomaly make the south of the Yangtze river more rain, have the same response relationship with the III rain type to La Nina Modoki mode.